Block copolymers are well-known items of commerce. Specifically, cationic polymerization of isobutylene is well-known and the use of various polyisocyanates in the formation of block copolymers has been described. Thus, Bauer et al. (Can. J. Chem., 48, 1251 (1970); J. Polym. Sci., A-1, 9, 1451 (1971)) describe cationic polymerization of isobutylene using alkyl-substituted phenols as chain-transfer agents. U.S. Pat. No. 3,689,593 discloses formation of graft copolymers by vinyl polymerization of an acrylate in the presence of various thiols, alcohols and amines as chain-transfer agents followed by reaction with a diisocyanate. Vinyl monomers are then polymerized in a solution of the isocyanate-terminated copolymers which are coupled to the polyolefin. Rahman et al. (J. Macromol. Sci.-Chem., A13(7), pp. 953-969 (1979)) describe block copolymers containing hydrophilic and hydrophobic sequences formed by reacting hydroxy-terminated polybutadiene with an isocyanate-terminated polyethylene oxide.
In U.S. Pat. No. 3,953,406 a mixture of hydrophilic and hydrophobic materials (e.g., polybutylene polyols) is admixed with a cross-linking agent and a diisocyanate followed by curing. U.S. Pat. No. 3,420,915 describes polymers formed from phenols and monomeric hydrocarbons which can be modified with diisocyanates and hydroxy polyethers. U.S. Pat. No. 3,859,382 describes anionic polymerization of olefins containing cyano, ester, nitro or amine groups followed by reaction with a polyisocyanate and subsequently with polyethers, polyamides etc. to form various block copolymers. In U.S. Pat. No. 3,989,768 graft copolymers are formed having various backbone segments linked to anionically-polymerized side chains which are said to include isobutylene (col. 9, line). Various linkages are formed by the use of isocyanates.
Numerous polyurethane block copolymers containing both hydrophobic and polyoxyalkylene blocks have also been described, e.g., U.S. Pat. No. 3,515,772 (col. 2, lines 11-23; col. 3, lines 11-15 and 38; and col. 6, line 16); U.S. Pat. No. 3,846,163 (col. 8, lines 25 and 28; col. 9, line 37; and col. 10, lines 75-col. 11, line 2); and U.S. Pat. No. 3,674,743 (cols. 1, 2, 4, 5, 6 and especially col. 6 lines 46-68 and col. 7, line 19).
U.S. Pat. No. 3,069,373 describes phenol-terminated polymers which are reaction products of various unsaturated petroleum resins with phenols. The phenol-modified resins are further reacted with polyepoxides. U.S. Pat. No. 4,101,473 describes phenol-blocked isocyanate prepolymers and polyurethanes prepared therefrom.
While the above patents and journal articles generally use various agents to couple the copolymer blocks, U.S. Pat. No. 3,418,359 relates to a process for producing olefin-polyalkylene oxide graft copolymers which are directly joined. U.S. Pat. No. 3,376,361 describes block copolymers containing oxymethylene groups along with co-monomers such as isobutylene.
U.S. Pat. No. 4,101,434 describes low temperature copolymerization of isobutylene and styrene in the presence of alkyl phenols. In U.S. Pat. No. 4,107,144 phenolic antioxidants are prepared by admixing a dialkyl phenol, a vinylic monomer (e.g., isobutylene), a Friedel Crafts or Lewis acid type catalyst, and an aprotic solvent; polymerizing the monomer at a temperature below 0.degree. C. and stopping the reaction when the polymer has attained a molecular weight of 1000 to 5000.